auth: Fix class name vs field name compilation by gcc
auth: Fix class name vs field name compilation by gcc

gcc fails to compile current master like this

In file included from ./service/client_state.hh:44,
                 from ./cql3/cql_statement.hh:44,
                 from ./cql3/statements/prepared_statement.hh:47,
                 from ./cql3/statements/raw/select_statement.hh:45,
                 from build/dev/gen/cql3/CqlParser.hpp:64,
                 from build/dev/gen/cql3/CqlParser.cpp:44:
./auth/service.hh:188:21: error: declaration of ‘const auth::resource& auth::command_desc::resource’ changes meaning of ‘resource’ [-fpermissive]
  188 |     const resource& resource; ///< Resource impacted by this command.
      |                     ^~~~~~~~
In file included from ./auth/authenticator.hh:57,
                 from ./auth/service.hh:33,
                 from ./service/client_state.hh:44,
                 from ./cql3/cql_statement.hh:44,
                 from ./cql3/statements/prepared_statement.hh:47,
                 from ./cql3/statements/raw/select_statement.hh:45,
                 from build/dev/gen/cql3/CqlParser.hpp:64,
                 from build/dev/gen/cql3/CqlParser.cpp:44:
./auth/resource.hh:98:7: note: ‘resource’ declared here as ‘class auth::resource’
   98 | class resource final {
      |       ^~~~~~~~

clang doesn't fail

Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@scylladb.com>
Message-Id: <20201118155905.14447-1-c9a32589e048e044184536f7ac71ef92fe82df3e@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla